Tuning EFI bikes

[Reddevil76]

I've been going thru info on Factory Pro, Dynojet, Yosh box, Techlusion

One question that keep raising in my mind. As I understand, there is a different fuel map for each individual gear.

The instructions for tuning is always related to tweaking at the different throttle positions.

But they've never specified if that process is repeated for each individual gear, (so each map is altered) or is it just done at a recommended gear.

Has anyone who has done any tuning comment?

And what does it mean when a shop says they tune it at 6th gear, WOT? Does it mean they only optimise the a/f at the scenario? If so, it's pretty useless as I can't see how many times I've gone WOT on 6th gear.

[Miles B]

It could be that there is only one fuel map per throttle opening, and the ECU uses a couple of multipliers for different gears? Like, multiply by 1.1 in 5th and 6th or something?

I believe there are 4 throttle opening maps.. but I could be wrong. What they mean is they are only tuning the WOT map, not the others. I would want the others tuned too. Nothing pisses you off like backfiring through the TBs and stalling while taking off slowly from the lights.

The engine ECUs I have dealt with don't have a full set of maps for each gear.. most just have like "21x40 load/rpm sites" (a Motec for example)... it means 21 maps for different load settings (either throttle opening or MAP sensor), and 40 points for different RPMs in each map. I don't think I've ever seen one with eg 21x40x6 (the 6 is for gears)... and I wouldn't think the Suzuki one would... I would think it would just use a % enrichment for the upper gears. So you tune WOT in one gear, you tune em all.

[Reddevil76]

Originally posted by Miles B
It could be that there is only one fuel map per throttle opening, and the ECU uses a couple of multipliers for different gears? Like, multiply by 1.1 in 5th and 6th or something?

I believe there are 4 throttle opening maps.. but I could be wrong. What they mean is they are only tuning the WOT map, not the others. I would want the others tuned too. Nothing pisses you off like backfiring through the TBs and stalling while taking off slowly from the lights.

The engine ECUs I have dealt with don't have a full set of maps for each gear.. most just have like "21x40 load/rpm sites" (a Motec for example)... it means 21 maps for different load settings (either throttle opening or MAP sensor), and 40 points for different RPMs in each map. I don't think I've ever seen one with eg 21x40x6 (the 6 is for gears)... and I wouldn't think the Suzuki one would... I would think it would just use a % enrichment for the upper gears. So you tune WOT in one gear, you tune em all.

The reason for my thinking is because of the ATRE which is said to trick the bike into using a chosen gear's map for the gears you wish to alter. For e.g. to use 6th gear's map for the 2nd & 3rd gears.

This led me to think that there is an individual map for each gear. Plus there is a gear position sensor on the bike, so being in which gear does some some signals somewhere.

Sorry, I'm not so much of a technical person, so that's only how far I deduce so far.

Basically, what you are saying is that there are different maps. But for different loads & engine speed, and not gear position?

So when tuning the bike, it is irrelevant to tune it at different gears, but rather, it is more important to subject the bike to different load/rpm scenarios and tune it at each scenario?

[Edwin]

Don't be confused Reddevil.

Tuning the EFI is like doing a carb. kit. It is NOT gear specific. I have tuned 3 bikes using Dynojets Power Commanders.

The main point to adjusting the EFI mapping is RPM & Throttle Opening. Hope this helped.

[Miles B]

Yep, that's what I'm saying. Chances are it just uses that gear position sensor to know when to "add a bit extra fuel than what's in the map".

You do want to get it tuned for more than just the WOT map. Not sure about bikes from the factory, but cars are tuned in all maps EXCEPT WOT to run at or very close to stoich. Factories usually tune the WOT map to be quite rich. If you make the engine breathe a lot better (exhaust, intake etc), you could start to run a little lean in the maps that used to sit close to stoich. Or it could just run like a bag of shit - and noone wants either.

[Reddevil76]

Originally posted by Edwin
Don't be confused Reddevil.

Tuning the EFI is like doing a carb. kit. It is NOT gear specific. I have tuned 3 bikes using Dynojets Power Commanders.

The main point to adjusting the EFI mapping is RPM & Throttle Opening. Hope this helped.

Ok, so let's use specific examples to be clearer. For e.g. The Teka SFI. They tell you to add/minus fuel by testing the 'snap' response at 10% throttle, 25% throtlle, etc.

And understandably, snapping the throttle from 10%, 25%, etc would be different if you are in a different gear. 10% throttle would result in diff rpm at different gear.

So while doing that, would you be in 6th gear or any other?

Lastly, I spend most of the time in 3rd to possible 5th gear in the tight local track. As such, if I chose to tune it at fourth gear.. is that acceptable?

[Edwin]

I agree with Miles.

Anyway, here's an example reddevil.

On my TLS, I had a bad stumble at 3K rpm. It was most noticeable while cruising at a partly open throttle while going about 40-50 mph. I adjusted the PC map to remedy the problem at the throttle opening & rpm where the problem was most noticeable, in the gear that it was most noticable.

I guess what I am trying to say here (and I think Miles is too) is to adjust your EFI to "cure" any problem or 'tune' for improvement in what ever gear the problem or lack of performance is most noticable and you are done. There is no need to tune a seperate map for every gear. It seems to me that fuel mapping stays constant throughout the gears while ingintion timing varies to compensate for load. I don't know this as fact, but I have had no problems tuning this way on the bikes that I have remapped. it was the same for the inline 4 as it was for the TL's I did.

[Reddevil76]

Originally posted by Edwin
I agree with Miles.

Anyway, here's an example reddevil.

On my TLS, I had a bad stumble at 3K rpm. It was most noticeable while cruising at a partly open throttle while going about 40-50 mph. I adjusted the PC map to remedy the problem at the throttle opening & rpm where the problem was most noticeable, in the gear that it was most noticable.

I guess what I am trying to say here (and I think Miles is too) is to adjust your EFI to "cure" any problem or 'tune' for improvement in what ever gear the problem or lack of performance is most noticable and you are done. There is no need to tune a seperate map for every gear. It seems to me that fuel mapping stays constant throughout the gears while ingintion timing varies to compensate for load. I don't know this as fact, but I have had no problems tuning this way on the bikes that I have remapped. it was the same for the inline 4 as it was for the TL's I did.

Ah.. ok. I get it.

Well, actually after recently doing the Joe V mod, I felt the bike performing better. There's no stumble or whatsoever. I'm just afraid this performance is at the expense of the bike running lean, so was looking at options to fine tune the bike. No noticeable problem to address directly though. It's like I'm riding it and asking myself," Great.. but could it have been better?"

Also, a phobia of running lean constantly bugging me is a result of my experience with my previous Honda. After the dealer had installed a dynojet carb kit and ran it on the dyno, the acceleration improved alot. At least on the street.

Then one week later, I brought it out for a run, ran it to near redline in top gear, and boom! White smoke outta the exhaust.

Later on, discovered that one of the plugs melted and shot a hole in one of the pistons.

Uanimous opinion is that my bike was running way too lean.

[Rupes]

I agree. The engine should be tuned at as many points as possible across the rev range times with as many throttle openings as possible. What gear its in should'nt make any difference to the engines performance except maybe where ram air is involved and thats difficult to simulate in your garage. The TRE mod and the GPS in general are used to modify the ignition map not the fuel map. By making the ecu think its in 4th or 5th gear it runs an ignition map with more advance.

As for shops tuning in 6th gear, I havent noticed the two places I've been too doing that except when doing a power run to print a graph showing Hp and torque, I'm not quite sure why they use 6th or for that matter 5th gear but its not because of a different fuel map. Maybe its to access the 5th or 6th gear ignition maps and therefore get a higher hp readout. Actually even then it shouldnt make a difference because power runs are done at wide open throttle at which point the timing should be advanced anyway...

[Edwin]

Nothing wrong with Dyno tuning, but on a bike with a ram air system on it, (like our TL's) I would think that it's a factor that doesn't get addressed on a Dyno.

I have always tuned my bikes by my "seat of the pants" gauge. I understand your concerns about running lean Bud. It's always a good idea to check your plugs while tuning your intake. Start your tuning on a fresh set of plugs. Alot of people who tune at home overlook this. Watch your operating temperatures also. A len bike will run noticably hotter. When you come to a stoplight check your temp. If it is higher than normal, the idle circuit is running lean.

I applaud your attitude on wondering "what if?" I have always said that when it comes to adjusting carbs (or EFI) tune till you think you get it perfect, then adjust it one more time. You never know until you try.

The PCII is a wonderful tool. I remember all too well what a hassle tuning a bank of carbs is, so in comparison EFI is a dream come true! Being that making adjustments is so easy to do, I suggest breaking down your tuning into sections: Low range, Medium, and Top End. Go one step further and tune each rpm range at a time according to throttle opening.

A good starting point would be a pre-made map that runs the best in your bike. Elevation and Enviromental conditions vary so a map that runs great in Montana probably won't run as well at sea level. Beside, no 2 bikes are exactly alike. With this in mind, it is my opinion that every pre-made map can be improved on.

Take the time to fiddle with your mapping and I think you will be very happy you did reddevil. Remember to check your plugs after every test run if you want to make absolutely sure you aren't running too lean.

**Note: on the subject of plugs, when it comes to the time when you are tuning for top end, use a new set of plugs. Ideally, it would be best to shut down the bike immediately after doing the run and do your plug check right there on the side of the road. That will be the most accurate reading you will get on your plugs. Tan to light brown is optimum. Off white is TOO LEAN. Do your run at WOT when checking your top end level. I hope this helped,

[Reddevil76]

Edwin, thanks for the very detailed reply. You've cleared alot of doubts for me.

I live in very humid and hot weather (Singapore), which stays constant all year round. Which makes alot of imported bikes run rich stock. I wonder if the Joe V mod made it just right or over shoot into running lean. My TLR is apparently a parallel import meant for the Canadian market.

And because of our bikes tendency to run rich, I was pondering if the Techlusion TFI will be useful (as it can only add fuel).

The PCII is indeed tempting, but financially prohibitive for me at the moment. Having just splashed out for Race Tech Gold Valves and Springs.

I might pick up a used Yosh box or grab a good PCII deal when I see one.

Meantime, I'll print out this replies for keepsake till this goodies became reality

[Reddevil76]

Originally posted by rupes
I agree. The engine should be tuned at as many points as possible across the rev range times with as many throttle openings as possible. What gear its in should'nt make any difference to the engines performance except maybe where ram air is involved and thats difficult to simulate in your garage. The TRE mod and the GPS in general are used to modify the ignition map not the fuel map. By making the ecu think its in 4th or 5th gear it runs an ignition map with more advance.

As for shops tuning in 6th gear, I havent noticed the two places I've been too doing that except when doing a power run to print a graph showing Hp and torque, I'm not quite sure why they use 6th or for that matter 5th gear but its not because of a different fuel map. Maybe its to access the 5th or 6th gear ignition maps and therefore get a higher hp readout. Actually even then it shouldnt make a difference because power runs are done at wide open throttle at which point the timing should be advanced anyway...

Rupes, thanks for the clarification!

To think I've wasted at least 6 months of my life believing the TRE fixes the six gear FUEL map onto the other gears. Even an online retailer of the ATRE in reply to my query told me it alters both fuel and ignition map. Seems like some people don't even know what they sell... doh...

[dsly1]

Get a TFI box.. and you can tune on the street without carrying a plampilot or notebook..

[Reddevil76]

Originally posted by dsly1
Get a TFI box.. and you can tune on the street without carrying a plampilot or notebook..

Yeah, I considered that. But it only allows the addition of fuel but not the removal.

In our extremely extremely humid weather, it is common for tuners here to lean out the fuel curves while tuning. The only occurence where they might add fuel is at 75% and above throttle. I dunno if after the airbox mod I am now on the rich or lean side, but I guess I'll need something that can minus as well as add.

[dsly1]

No way your going to lean out ANY fuel on the TLR from stock